Rotary pump or motor



y 30, 1939- E. K. BENEDEK 2,160,352

' ROTARY PUMP OR MOTOR Original Filed March 12, 1935 5 sheets sheet 1SYVUCMM ELEKKEIENEUEK- y 193'9- E. K. BENEDEK 2,160,352

ROTARY PUMP ORMOTOR Original Filed March 12, 1935 3 Sheets-Sheet 2 E1:EKKEIENEDEK May 30, 1939. I E. K. BENEDEK 2,160,352

ROTARY PUMP OR MOTOR Original Filed March 12; 1935 3 Sheets-Sheet 5 $9Q) Q 16' \J t) P 4/ Q) I $2 4 Q Q 17- U ELEKKBENEDEK.

Patented May 30, 1939 UNITED STATES ROTARY PUMP on Moron. Elek K.Benedelr, Bucyrlls, Ohio Original application March 12, 1935, Serial No.

10,691. Divided and this application September 2,1938, Serial No.228,136

4 Claims.

The invention relates to a variable delivery, radial piston, hydraulicpump'or motor ofthe rotary reactance type and is a division of mycopending application, Serial No. 10,691, filed 5 March 12, 1935.

Heretofore, pumps and motors of this character have been provided withT-head pistons operating in chordal grooves in a rotary reactance.Likewise, as described in my copending application, Serial No. 50,671,filed November 20, 1935, pistons having a plurality of rolling pins havebeen provided for this purpose, the pins being rotatably mounted in thepiston head,

one pin being solely for radial load and at least two additional pinsbeing for torque transmission. Such pins operate in chordal grooves ofthe reactance broadly in the same manner as a T-head, both the T-headand the multi-pin and roller type of piston head operating to transmitboth radial thrust and torque, from the cylinder barrel .to thereactance.

Again, other types of rotary pumps and motors have been provided whereina single crosspin is .rotatably mounted in the head of the piston, thiscrosspin being in rolling engagement with arcuate grooves which are inthe reactance rotor and are concentric with the 'rotative axis of thereactance rotor.

In the above-described T-head type and multipin and roller type ofpiston, the grooves and piston heads must cooperate not onlytoreciprocate the pistons radially of the barrel but also to effect, asnearly as possible, synchronous rotation of the cylinder barrel androtary reactance. In rotary reactance types of pumps and motorsemploying T-head pistons or equivalent, synchronous rotation of thebarrel and reactance is necessary to effect proper timing between thecylinder ports of the cylinder barrel and the valving ports or bridgesof the pintle. In the rotary floating reactance type of pumps or motorsemploying a single crosspin only in each piston and circular grooves inthe rotary reactance for cooperation with the pins, the problem ofproper timing is not so acute as there the relation of all parts of thegroove to the dead center line of the bridges of the pintle ismaintained in all relative positions. of the two rotors withoutsynchronization.- But even in this latter type of pumps and '50 motorsthe piston must withstand not only the hydraulic load but also thetorque. The crosspins, however, in this latter case, may have to spinaround their axes at an enormous speed, due to the floating connectionbetween the rotors.

One oi'the principal objects of the present in- Gil vention is toprovide a rotary radial piston pump or motor of the synchronized typeemploying a single rotatable crosspin only for each piston incooperation with a chordal groove in the rotary reactance with meansdisassociated from the piston, pin and groove for effecting synchronousrotation between the cylinder barrel and the rotary reactance, therebyassuring the proper valving relation between the pintle and cylinderswhile at the same time making possible the use of a more effectiveguiding means for the head of the piston by eliminating the spinning ofcrosspins about their axes and simplifying the design of the pump ormotor.

Before referring to the specific embodiment herein shown for purposes ofillustration, it should be noted that in a highpressure, high speed pumpor motor, both load and torque transmission are of prime importance, ifsmooth, quiet and efllcient operation is to be maintained.Correlatively, the resultant valving cooperation must be maintained at ahigh degree of accuracy in order to prevent the entrapment ofsubstantially incompressible working fluid used in such pumpsand-motors. Improper timing between the pintle and cylinder ports oftendevelops destruc tive knocks, vibrations, and. noise, due either toexcessive compression or to improper filling of the cylinders with the"working fluid. Such knocks and noise evidence poor volumetric efliciencyand improper operation due to improper timing. More specifically, it isnecessary, in order to eliminate excessive compression and improperfilling of the cylinders, to assure that the pistons complete theirstrokes to their exact ends and at the exact time that the correspondingcylinder ports are at the dead center position of the valving bridgesarranged between the valvin ports of the valving pintle.

In other words, the pistons in their in and out dead center positionsmust be" synchronized in space and time with the coincidence of thecylinder ports and the respective bridge centers.

It is, therefore, another object of the present invention to provide astructure in which the pistons reach theexact position desired radiallyat the instant that the associated cylinders are in proper relation tothe dead center line of the pintle bridges.

Other objects and advantages will become apparent from the followingspecification, wherein reference is made to the drawings in which:

Fig; 1 is a horizontal axial sectional view of a rotary pump or motorembodying the principles of the present invention, and is taken on aplane indicated by the line in Fig. 2;

Fig. 2 is a vertical sectional view of the pump pintle 2 is fixedlymounted. The valve pintle 2' hasdiametrically opposite, reversiblevalving ports 3 and 4, respectively, with timing bridges 5 disposedtherebetween.

Rotatably'mounted in the casing and preferably upon the pintle 2 is acylinder barrel 6 having a set of cylinders I which are spaced from eachother circumferentially of the barrel. Each cylinder I has a cylinderport 8 arranged for successive cooperation with the ports 3 and 4 uponrotation of the barrel. The barrel has a radial flange portion Sin whichare radial guideways I0 and clearance holes Reciprocably mounted in eachcylinder 1 is a piston I2 having an enlarged head J3 which isreciprocable in and guided within the'guideways II) of the barrelflange.

Rotatably mounted in each piston head and preferably on anti-frictionbearings is a crosspin l4, each pin l4 extending parallel to the axis ofrotationof the barrel. The ends of each pin extend beyond the laterallimits of the head l3 into a position for cooperating with a rotaryreactance in a manner to effect reciprocation of the pistons consequentupon rotation of the barrel and eccentrically disposed reactance.

The reactance comprises a pair of rigid generally circular ring membersIt anti-frictionally supported on bearings II in an adjustable reactancestator I8. I Carried by the members I6 are reactance rings IS, thereactance rings beingrigid with the associated members It. The ,membersIS with the reactance rings l9 therebtween are secured against axialseparation by suitable bolts 20 extending through the clearance holes llof the barrel flange, thus forming a rigid, substantially unitary rotaryreactance structure, in cooperation with tubular spacers as at Ma.

Each of the reactance rings l9 has a series of chordal grooves 2|, onegroove being provided in each ring for each piston pin. The ends of eachcrosspin 4 are received in rolling engagement within opposite grooves 2|of the rings l9 The reactance stator I8 is mounted in the casing formovement diametrically of the casing along a path which is parallel tothe median .or

.dead center plane or line of the diametrically opposite bridges 5,which plane coincides with the line l-| in Fig. 2. Thus, by adjustmentof the stator |8 to difierent positions along said path, the reactancerings are positioned with their axis either coincident with or parallelto and offset from the pintle axis at either side of the pintle axis.This adjusts the stroke of the pump or motor in either direction ofrotation.

The valve port 3 is connected by suitable pin tle ducts 25 with a mainport 25, and the pintle ducts 2i connect the port 4 with a main port 28,thejmain port 28 being arranged opposite to ,the'port 26 diametricallyof the pintle.

The barrel 6 is provided at one end with an impeller stand isadditionally supported at the a positive driving coupling is provided.As better illustrated in Fig. 3, this coupling comprises an O-shapedinterponent 40 which partially surrounds the barrel near one end and hasdiametrically opposite, parallel, inner faces 4| which are arranged forengaging'complementary outer faces 42 on the adjacent end of the barrelso that the interponent 40 has, inner faces 43 which extend at rightangles to the faces 4| and are spaced apart from each other a distancepermitting-the maximum distance of reciprocation I that will occurbetween the interponent and the end of the barrel during operation ofthe pump or motor at maximum stroke. Likewise the interponent hasexternaLparallel faces 45 which extend at right angles to the surfaces4|.

The members It of the rotary reactance are provided with internal faces46 parallel and complementary to the faces 45' of the interponent 40.The members It also have internal faces 41 spaced apart a distancepermitting the maximum distance of reciprocation that will occur betweenthe interponent 40 and the reactance members It.

.Thus, the interponent positively drivingly connects the barrel androtary reactance regardless of the eccentricity of the barrel andreactance,

one component of the eccentricity being compensated for through thecooperation of the surfaces 4| and 42, and the other component of theeccentricity being compensated for by the cooperation of the surfaces 45and 46.

In the form illustrated, anti-friction needle roller bearings, such asindicated at 48, are interposed between the complementary, cooperatingfaces of the interponent and the barrel and of the interponent and thereactance. Accordingly, all torque transmission between the barrel andthe reactance is effected through the medium of the interponent, and thepistons, cylinders and crosspins are relieved from all torquetransmission and have only to receive or deliver pressure fluid underdirect radial thrust.

The operating grooves 2| of the reactance rotor v are not only chordalbut are at right angle to a radius from the center of the pintle 2through a dead center position of the bridges 5 when the associatedpiston I2 is passing its dead center position of reciprocation and thesepositions of V each piston occur when the associated cylinder 1 is atthe dead center line of the pintle bridges 5.

Further, adjustment of the reactance is exactly along the dead center:line of the pintle bridges 5. It is only when these relations are fullysatisfied that precise valving or timing relation is provided. Suchtiming is necessary be-' cause working fluid under high speed operationmust remain solid, that is, free from foaming. 'vapor or air occlusions.Otherwise there will be noise and low volumetric efficiency and,obviously, were the oil compressibledue to air bubbles and the like,proper timing could not be obtained, and the power development would notbe positive, but springing.

The pins l4 can roll freely along the grooves 2| since they are relievedfrom all torque transmission. Since only one pin is necessary in thisstructure, the piston head may be narrower fore and aft of the path ofrotation and consequently the flange 9 of the barrel 6 with longguideway l0 radial guideways in the torque flange of the barrel arecombined with the advantages afforded by chordal reactance grooveswithout the binding of the conventional T-head. Further, the precisetiming between the pistons and the valve is favorably alected by thesynchronous drive between the barrel and the reactance, withoutburdening the pistons and cylinders with torque transmission between thebarrel and reactance. Ordinarily a chordal or tangential slot could beused only with a T-head piston or a multi-pin piston, and either theT-head or multi-roliers i5 heretofore have been necessary to bring thedead center line of the pintle bridges coincident with the axis of thepiston when the piston is in the innermost and outermost position, thatis, dead center position. With only one rolling pin and an arcuateslot,this would. not occur, and the amount which the piston was ofi of deadcenter when passing the dead center line of the bridges would be theerror in timing. This valving problem does not exist in the case ofcircular grooves because the adjustment of the groove as, a circle willalways permit reasonably good valving conditions but introduces otherundesirable factors. With floating or differential rotary reactances,onesingle crosspin gives perfect timingbetween pintle and cylinderswith'a simple circular groove only in the reactance. Such pins may,however,

have to spin about their own axes at destructivspeeds, to compensate forthe differential motion ofthe reactance with respect to the cylinderbara rel. The tangential grooves furnish pure harmonic impulses whilethe pistons are relieved from the heave torque transmission.

Having thus described my invention, I claim': 1. In a hydraulic pump ormotor of the rotary o radial piston type including a rotatable barrelhaving a plurality of circumferentially spaced radial cylinders, valvemeans therefor, pistons in the cylinders, respectively: arotatablereactance means for said pistons and adjustable to dispose 5 itsrotative axis coincident with or parallel to and offset from therotative axis of the barrel, said reactance means having chordal groovesopening toward the zone of the pistons, a single crosspin rotatablymounted in each piston, an 50 end portion of each crosspin extendingbeyond the associated piston transversely of the path of rotation of thepistons, and the extending end portion of the pins being received inassociated grooves.

2. In a hydraulic pump or motor of the rotary radial piston typeincluding a rotatable barrel having a. plurality of circumferentiallyspaced radial cylinders, valve means therefor, pistons in the cylinders,respectively, a rotatable reactance means for said pistons andadiustable to its rotative axis coincident with or parallel to andoffset from the rotative axis'oi' the barrel, said reactance meanshaving chordal grooves opening toward the zone of the pistons, a single.crosspin rotatably nounted in each piston, an end portion of eachcrosspin extending beyond the associated piston transversely of the pathof rotation of the pistons, and the extending end portion of the pinsbeing received in associated grooves, and means disassociatedfrom saidpistons, pins and grooves and drivingly connecting the barrel andreactance means forsynchronous rotation.

3. In a hydraulic'pumpor motor of the rotary radial piston typeincluding a rotatable barrel having a plurality of circumferentiallyspaced radial cylinders, valve means therefor, pistons inv thecylinders,'res'pectively, a rotatable reactan means for said piston andbeing adjustable to dispose its rotative axis coincident with orparallel to and oflset from the rotative axis of the barrel, said barrelhaving a radial flange in the zone of the cylinders and radial guidewaysin said flange,

said pistons having heads reciprocable radially of thebarrei in saidguideways, said reactance means having chordal grooves opening towardthe zone of piston heads, crosspins rotatably mounted one only in eachpiston head, the end portions of each crosspin extending beyond theassociated piston head transversely of the path of rotation of thepistons, the extending end portions of the pins being received inassociated grooves, respec-' tively, and means in addition to saidpistons, pins and grooves, drivingly connecting the barrel and reactancemeans for synchronous rotation.

4. In a hydraulic pump or motor of the rotary radial piston typeincluding a rotatablebarrel having a plurality of circumferenti'allyspaced radial cylinders, valve means for the cylinders. pistonsreciprocable'dn the cylinders, respectively,

v a rotatable reactance means for said pistons and being adjustable todispose its rotative axis 00- toward the pistons and flange, crnsspinsrotatably mounted one crosspin only in each piston, the end portions ofeach crosspin extending beyond the associated piston transversely of thepath of travel.

of the pistons, and the extending end portions of the pins beingreceived in opposite, associated chordal grooves ofsaid-walls,'respectively, and

means in addition to said pistons,- pins and i grooves, drivinglyconnecting the barrel and reactance means for synchronous rotation.

